93
13
MAINTENANCE
2001 NEW
■
Resetting the CPU
When first applying power or when the function does
not seem to be operating normally, reset the CPU as
follows:
q
Make sure the transceiver power is OFF.
w
While pushing [M-CL] and [F-INP], push [POWER]
for 1 sec. to turn power ON.
• The internal CPU is reset.
• The transceiver displays its initial VFO frequency when
resetting is complete.
e
Correct the set mode settings after resetting, if de-
sired.
NOTE:
Resetting
CLEARS
all programmed con-
tents in memory channels and returns programmed
values in set mode to default values.
■
Frequency calibration
(approximate)
A very accurate frequency counter is required to cali-
brate the frequency of the transceiver. However, a
rough check may be performed by receiving radio sta-
tion WWV, or other standard frequency signals.
CAUTION:
Your transceiver has been thoroughly
adjusted and checked at the factory before being
shipped. You should not calibrate frequencies, ex-
cept for special reasons.
q
Push [SSB] to select USB mode.
w
Push [PBTC] for 1 sec. to clear the PBT settings
and make sure that the RIT/
∂
TX function is not ac-
tivated.
e
Set the frequency to the standard frequency station
minus 1 kHz.
• When receiving WWV (10.000.00 MHz) as a standard
frequency, set the operating frequency for 9.999.00 MHz.
• Other standard frequencies can also be used.
r
Push [MENU] several times to select
M1
or
M2
, if
necessary.
t
Push [MENU] for 1 sec. to select the set mode
screen.
y
Push [F1
≤
] or [F2
≥
] several times to select the
CAL. Marker
item.
u
Rotate the tuning dial clockwise to turn the calibra-
tion marker ON.
• Side tone may be heard.
i
Adjust [CAL] pot on the rear side of the transceiver
for a zero beat with the received standard signal.
• Zero beat means that two signals are exactly the same
frequency, resulting in a single tone being emitted.
o
Rotate the tuning dial counterclockwise to turn the
calibration marker OFF.
!0
Push [MENU] to exit set mode.
C A L . M a r k e r
5
O N
[SSB]
[MENU]
[PBTC]
[RF/SQL] [AF] [P.AMP/ATT]
[CLEAR]
[RIT]
[CAL]
• Calibration marker item
[POWER]
[F-INP] [M-CL]
IC-7400.qxd 02.4.2 11:36 Page 93
